If you've used Steam a lot you've probably noticed a few games where Steam tries to install something every time an application is started. This application is intended to tell Steam it is installed so it can quit trying.

1) Select the VDF for the application you're trying to install. Not all applications have prerequisites so not all applications have a VDF file to select. The VDF usually resides in the application's install directory as either install_APPID.vdf or installscript.vdf. Either should work but I would recommend using installscript.vdf when both are available.

2) Input the application ID number for the product. It should show up in the drop down list acquired from Steam but it might not. The easiest way to get it is to find the Steam store page for the program. For example, here is the full URL to the Dishonored store page and I have bolded the application ID number in it. Input that into the "app ID" field of the program: http://store.steampowered.com/agecheck/app/205100/
Without agecheck: http://store.steampowered.com/app/205100/

3) Click refresh to try to parse the installscript and search the application ID registry. If it was successful, it will show a list of prerequisite applications in the list box below.

4) Check all the unchecked boxes and start the application. Steam should no longer prompt to install anything. Note: If the prerequisite is, in fact, not installed, right-click on it and select Install to start the installer.

Title

AppID

Prerequisite (process if not obvious)

1

Assassin's Creed III

208480

VCRedist, UplayLauncher, kb971512x86, kb971512x64

2

Command & Conquer 4: Tiberium Twilight

47700

.NET 3.5 SP1

3

Darksiders II

50650

DirectX

4

Dishonored

205100

PhysXRedist (msiexec)

5

Hard Reset

98400

DirectX

6

Mafia II

50130

PhysX2

7

Wasteland Angel

46520

MS VC++ 2010 Redist

If you know of an application that should be added to the list, post it or private message me. Please provide the title, app ID, and information about the bugged prerequisite in the message.

Great idea! Anyway to make it work with new applications? I have about 20 instances of directX installed on my computer due to steam installing it for new games, even though I already have DirectX........

If you install the software but don't run it (needs the VDF file) and know the App ID, it should be able to tell Steam they are all installed before even running it. You have to remember to run Prerequisite Modifier for Steam prior to starting the game though.

Edit: For coders out there, the VDF parser is exposed in the binary if you wanted to use it in your own .NET application. It isn't completely finished though (no Write method) because I didn't see much use in finishing it. If someone has use of it, let me know and I'll finish it.

Updated to version 1.0.1 which fixes a bug where VDF file listed values before subkeys. This problem prevented the program from working correctly on Assassin's Creed III installscript.vdf (and likely others). It now works for changing AC3's prerequisites. I also added AC3 to the list of "applications known to be helpful on."

Updated to version 1.0.2 which fixes a bug where the end of the file doesn't terminate as expected and it would try to read data that did not exist. I noticed this issue on Mafia II installscript.vdf (Steam tries to install "PhysX2" every time the game runs). It should now be fixed.

Edit: If someone finds a game that has problems, attach the VDF you used to your post (probably have to zip it first) and provide the Steam App ID and I'll see if I can fix it.

Updated to version 1.0.3 which allows PMS to work on runasadmin.vdf where there was no "installscript" section. I also made it auto-fill the VDF location and App ID from command line parameters if given (simply put them in that order and quotes around the path if it has spaces).